United Air Lines was founded in 1926 by Walter Varney in Boise, Idaho. Its original name was Varney Airlines, and the firm delivered air mail for the U.S. Post Office. The company grew and became a conglomerate of airlines, incorporating many routes. The heads of several airlines in the conglomerate got together with the postmaster general in 1930 to divide up and assign the air mail routes. That so-called Air Mail Scandal" quickly dissolved; the air mail routes were given to the U.S. Army Air Corps.
During World War II, the company benefited from involvement with the training of ground crews and materials transportation. Following the war, the company boomed from the demand for air travel. The airlines eventually encountered turmoil and labor unrest with the enactment of the Airline Deregulation Act of 1978. That act ushered in major decreases in profit and the company was forced to come up with new ways to make money, including the Mileage Plus frequent flyer program, acquiring the Westin and Hilton Hotel chains and the Hertz car rental company. The company also managed to buy out other airlines to expand its network of destinations.